Development and evaluation of a symposium model for building physician-scientist skills, connections, and persistence

• Text
• PDF

Abstract

High rates of physician-scientist attrition from the investigative workforce remain a significant problem despite the development of dedicated programs and initiatives designed to address the unique challenges faced by physician-scientists. However, many of these efforts are restricted to single career stages of physician-scientist training or to a single medical specialty, which may limit opportunities for beneficial vertical and horizontal mentorship regarding overcoming common career obstacles. Here, we outline the development of a physician-scientist symposium to break down silos and enable productive interactions between physician-scientists across career/training stages, academic and scientific disciplines, and medical specialties. Participants were (a) mixed in small-group problem-based discussions, (b) participated in a cross-specialty keynote panel on overcoming barriers in a physician-scientist career, and (c) took part in skill-building workshops. Attendees indicated that they fostered new connections, developed new skills to overcome career challenges, and increased their commitment to persevering in a career as a physician-scientist. Positive evaluations were not dependent on attendee career/training stage or gender. We suggest these elements of the symposium curriculum may be easily adapted for inclusion in a wide variety of physician-scientist training formats.

Authors

Kevin F. Dowling, Shohini K. Ghosh-Choudhary, Neil Carleton, Kathleen Prigg, Richard A. Steinman

An insider’s guide to understanding and obtaining an NIH K career development award

• Text
• PDF

Abstract

Physician-scientists in academic medical centers require extramural grant support to launch and maintain their research careers. In order to cultivate the next generation of biomedical researchers, including physician-scientists, the NIH supports multiple career development (K series) awards. For many, their first experience in grant writing is composing a career development award (CDA) application. From the applicant’s perspective, this process can be difficult. For one, NIH institute–specific differences between the same K mechanism can be confusing. Additionally, the importance of the various elements that make up the K application are frequently misunderstood. Furthermore, many K applications will not be funded on the initial submission; therefore, the need to resubmit an application should not be viewed as a sign of failure, but rather can be viewed as an element of resilience in biomedical research. In this piece, we aim to provide guidance for aspiring K applicants — in particular, from the reviewer perspective — with the intent of making the application process more understandable. We offer dos and don’ts on different components of the K application, advice on when to reach out to a program officer, and tips on resubmission. Our overarching goal is to provide support for prospective K applicants in their effort to obtain a K award. While targeted to K applications, most of the contents of this summary apply to any CDA.

Authors

Don C. Rockey, Kyu Y. Rhee, Christopher S. Williams, Jatin M. Vyas, Charles W. Emala, Emily J. Gallagher

Radiosensitizing the SUMO stress response intensifies single-dose radiotherapy tumor cure

• Text
• PDF

Abstract

Single-dose radiotherapy (SDRT) is a highly curative modality that may transform radiotherapy practice. Unfortunately, only ~50% of oligometastatic lesions are SDRT treatable due to adjacent radiosensitive normal organs at risk. Here, we address the extent to which an antiangiogenic drug, VEGFR2-antagonist DC101, radiosensitizes SDRT using murine MCA/129 fibrosarcomas and Lewis lung carcinomas, which display a dose range for SDRT lesional eradication virtually identical to that employed clinically (10–30 Gy). SDRT induces unique tumor cure, stimulating rapid endothelial acid sphingomyelinase (ASMase)/ceramide signaling that yields marked vasoconstriction and perfusion defects in tumor xenografts and human oligometastases. Ensuing tumor parenchymal oxidative damage initiates a SUMO stress response (SSR), which inactivates multiple homologous recombination repair enzymes, radiosensitizing all tumor types. While VEGF inhibits neo-angiogenic ASMase, optimal radiosensitization occurs only upon antiangiogenic drug delivery at ~1 hour preceding SDRT. Obeying these principles, we find DC101 radiosensitizes SSR, DNA double-strand break unrepair, and tumor cure by 4–8 Gy at all clinically relevant doses. Critically, DC101 fails to sensitize small intestinal endothelial injury or lethality from the gastrointestinal–acute radiation syndrome. Whereas normal tissues appear not to be under VEGF regulation nor sensitized by our approach, its application might render many currently intractable oligometastatic lesions susceptible to SDRT eradication.

Authors

Jin Cheng, Liyang Zhao, Sahra Bodo, Prashanth K.B. Nagesh, Rajvir Singh, Adam O. Michel, Regina Feldman, Zhigang Zhang, Simon Powell, Zvi Fuks, Richard Kolesnick

Tumor suppressors in Sox2-mediated lung cancers promote distinct cell-intrinsic and immunologic remodeling

• Text
• PDF

Abstract

Non–small cell lung cancer (NSCLC) largely consists of lung squamous carcinoma (LUSC) and lung adenocarcinoma (LUAD). Alterations in the tumor protein p53 (TP53) and phosphatase and tensin homolog (PTEN) tumor suppressors are common in both subtypes, but their relationship with SOX2 is poorly understood. We deleted Trp53 or Pten in a C57BL/6 Sox2hi Nkx2-1–/– Lkb1–/– (SNL) genetic background and generated a highly metastatic LUSC cell line (LN2A; derived from a Sox2hi mouse model, followed by Trp53, Pten, and cyclin dependent kinase inhibitor 2A [Cdkn2a] deletion). Histologic and single-cell RNA-Seq analyses corroborated that SNL mice developed mixed tumors with both LUAD and LUSC histopathology while SNL-Trp53 and SNL-Pten mice developed LUAD and LN2A tumors that retained LUSC morphology. Compared with SNL mice, additional loss of Trp53 or Pten resulted in significantly reduced survival, increased tumor burden, and altered tumor mucin composition. We identified a subcluster of CD38+ tumor-associated inflammatory monocytes in the LN2A model that was significantly enriched for activation of the classical and alternative complement pathways. Complement factor B (CFB) is associated with poor survival in patients with LUSC, and we observed the LN2A model had significantly improved survival on a Cfb–/– background. Our findings demonstrate a cooperative role of Trp53 and Pten tumor suppressors in Sox2-mediated NSCLC tumor progression, mucin production, and remodeling of the immune tumor microenvironment.

Authors

Nisitha Sengottuvel, Kristina M. Whately, Jennifer L. Modliszewski, Rani S. Sellers, William D. Green, Weida Gong, Allison T. Woods, Eric W. Livingston, Katerina D. Fagan-Solis, Gabrielle Cannon, Lincy Edatt, Hong Yuan, Aaron C. Chack, Yazmin Sanchez, Katherine Zhou, Alyaa Dawoud, Jarred M. Green, Virginia Godfrey, J. Justin Milner, Gaorav P. Gupta, Chad V. Pecot

Loss of genome maintenance is linked to mTOR complex 1 signaling and accelerates podocyte damage

• Text
• PDF

Abstract

DNA repair is essential for preserving genome integrity. Podocytes, postmitotic epithelial cells of the kidney filtration unit, bear limited regenerative capacity, yet their survival is indispensable for kidney health. Podocyte loss is a hallmark of the aging process and of many diseases, but the underlying factors remain unclear. We investigated the consequences of DNA damage in a podocyte-specific knockout mouse model for DNA excision repair protein Ercc1 and in cultured podocytes under genomic stress. Furthermore, we characterized DNA damage-related alterations in mouse and human renal tissue of different ages and patients with minimal change disease and focal segmental glomerulosclerosis. Ercc1 knockout resulted in accumulation of DNA damage and ensuing albuminuria and kidney disease. Podocytes reacted to genomic stress by activating mTOR complex 1 (mTORC1) signaling in vitro and in vivo. This was abrogated by inhibiting DNA damage signaling through DNA-dependent protein kinase (DNA-PK) and ataxia teleangiectasia mutated (ATM) kinases, and inhibition of mTORC1 modulated the development of glomerulosclerosis. Perturbed DNA repair gene expression and genomic stress in podocytes were also detected in focal segmental glomerulosclerosis. Beyond that, DNA damage signaling occurred in podocytes of healthy aging mice and humans. We provide evidence that genome maintenance in podocytes is linked to the mTORC1 pathway and is involved in the aging process as well as the development of glomerulosclerosis.

Authors

Fabian Braun, Amrei M. Mandel, Linda Blomberg, Milagros N. Wong, Georgia Chatzinikolaou, David H. Meyer, Anna Reinelt, Viji Nair, Roman Akbar-Haase, Phillip J. McCown, Fabian Haas, He Chen, Mahdieh Rahmatollahi, Damian Fermin, Robin Ebbestad, Gisela G. Slaats, Tillmann Bork, Christoph Schell, Sybille Koehler, Paul T. Brinkkoetter, Maja T. Lindenmeyer, Clemens D. Cohen, Martin Kann, David Unnersjö-Jess, Wilhelm Bloch, Matthew G. Sampson, Martijn E.T. Dollé, Victor G. Puelles, Matthias Kretzler, George A. Garinis, Tobias B. Huber, Bernhard Schermer, Thomas Benzing, Björn Schumacher, Christine E. Kurschat

Multiomics analysis unveils an inosine-sensitive DNA damage response in neurogenic bladder after spinal cord injury

• Text
• PDF

Abstract

Spinal cord injury (SCI) evokes profound dysfunction in hollow organs such as the urinary bladder and gut. Current treatments are limited by a lack of molecular data to inform novel therapeutic avenues. Previously, we showed that systemic treatment with the neuroprotective agent inosine improved bladder function following SCI in rats. Here, we applied integrated multi-omics analysis to explore molecular alterations in the bladder over time and their sensitivity to inosine following SCI. Canonical signaling pathways regulated by SCI included those associated with protein synthesis, neuroplasticity, wound healing, and neurotransmitter degradation. Upstream regulator and causal network analysis predicted multiple effectors of DNA damage response signaling following injury, including poly-ADP ribose phosphorylase-1 (PARP1). Markers of DNA damage (γH2AX, ATM/ATR substrates) and PARP activity were increased in bladder tissue following SCI and attenuated with inosine treatment. Inosine treatment also attenuated oxidative DNA damage in rat bladder cells in vitro. Proteomics analysis suggested that SCI induced changes in protein synthesis–, neuroplasticity-, and oxidative stress–associated pathways, a subset of which were shown in transcriptomics data to be inosine sensitive. These findings provide insights into the molecular landscape of the bladder following SCI and identify key inosine-sensitive pathways associated with injury.

Authors

Ali Hashemi Gheinani, Bryan S. Sack, Alexander Bigger-Allen, Hatim Thaker, Hussein Atta, George Lambrinos, Kyle Costa, Claire Doyle, Mehrnaz Gharaee-Kermani, Susan Patalano, Mary Piper, Justin F. Cotellessa, Dijana Vitko, Haiying Li, Manubhai Kadayil Prabhakaran, Vivian Cristofaro, John Froehlich, Richard S. Lee, Wei Yang, Maryrose P. Sullivan, Jill A. Macoska, Rosalyn M. Adam

Dysregulated synaptic gene expression in oligodendrocytes of spinal and bulbar muscular atrophy

• Text
• PDF

Abstract

Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease caused by an expanded CAG repeat in the androgen receptor (AR) gene. To elucidate the cell type–specific temporal gene expression in SBMA, we performed single-nucleus RNA sequencing on the spinal cords of an SBMA mouse model (AR-97Q). Among all cell types, oligodendrocytes had the highest number of differentially expressed genes before disease onset. Analysis of oligodendrocyte clusters suggested that pathways associated with cation channels and synaptic function were activated before disease onset, with increased output from oligodendrocytes to neurons in AR-97Q mice compared with wild-type mice. These changes in the early stages were abrogated at the advanced stages. An oligodendrocyte model of SBMA showed phenotypes similar to those of AR-97Q mice at early stages, such as increased transcriptional changes in synapse organization, and Ca2+ imaging of oligodendrocytes in AR-97Q mice revealed the increased Ca2+ responses. A coculture system of primary rat oligodendrocytes and neurons revealed that the mutant AR in oligodendrocytes affected the activity and synchronization of neurons. These findings suggest that dysregulated cell-to-cell communication plays a critical role in early SBMA pathology and that synaptic or ion channel–related proteins, such as contactin associated protein 2 (Cntnap2) and NALCN channel auxiliary factor 1 (Fam155a), are potential therapeutic targets for SBMA.

Authors

Madoka Iida, Kentaro Sahashi, Tomoki Hirunagi, Kenji Sakakibara, Kentaro Maeda, Yohei Iguchi, Jiayi Li, Yosuke Ogura, Masaki Iizuka, Tomohiro Akashi, Kunihiko Hinohara, Shouta Sugio, Hiroaki Wake, Masahiro Nakatochi, Masahisa Katsuno

Biological sex and age influence GS-9620 activity ex vivo

• Text
• PDF

Abstract

Toll-like receptors (TLRs) are being explored to enhance immunity in HIV cure strategies. The TLR7 agonist GS-9620 promotes immune activation, reactivates latent HIV, and delays viral rebound in some people with HIV. Previous work has shown that biological sex influences TLR7 signaling. This study examined the interplay between biological sex, age, and the sex hormones 17β-estradiol, progesterone, and testosterone on GS-9620’s ability to promote cytokine secretion and activate CD4+ T, CD8+ T, and NK cells ex vivo. Interestingly, sex hormones had no effect on GS-9620–mediated immune activation or cytokine induction. However, we found that GS-9620 activity was influenced by age only in female donors. Further, we found that GS-9620–mediated CD4+ T cell activation was positively correlated with the induction of IFN-γ and IL-12, while CD4+ T cell activation and IL-12 production were negatively correlated with age. Additionally, CD8+ T cell activation was positively correlated with IFN-γ production. Mechanistically, IFN-γ was sufficient to promote higher immune activation of both CD4+ and CD8+ T cells in female versus male donors. In conclusion, biological sex and age, but not sex hormones, influence GS-9620–mediated immune activation. Understanding these factors will help in designing and evaluating future clinical trials using GS-9620 for an HIV cure.

Authors

Carissa S. Holmberg, Callie Levinger, Adam R. Ward, Alberto Bosque

PCSK9 deficiency promotes the development of peripheral neuropathy

• Text
• PDF

Abstract

Proprotein convertase subtilisin/kexin type 9 (PCSK9) induces the hepatic degradation of the low-density lipoprotein receptor (LDLR), thereby increasing the concentration of LDL-cholesterol in the blood. Beyond its effects on LDL, recent studies have reported pleiotropic effects of PCSK9, notably in septic shock, vascular inflammation, viral infection, and cancer. While the functional and structural integrity of peripheral nerves are critically influenced by circulating lipids, the effect of PCSK9 on the peripheral nervous system remains unknown. In this study, we investigated the consequences of PCSK9 deficiency on peripheral nerves. We found that PCSK9 deletion in mice leads to peripheral neuropathy, characterized by reduced thermal and mechanical pain sensations. PCSK9-deficient mice also presented with skin structural changes, including a reduction in nociceptive Schwann cell number, axonal swelling of Remak fibers, and hypomyelination of small nerve fibers. Interestingly, the peripheral nerves of PCSK9-deficient mice showed an upregulation of CD36, a fatty acid transporter, which correlated with increased nerve lipid content, structural mitochondrial abnormalities, and acylcarnitine accumulation. Our findings demonstrate that PCSK9 plays a critical role in peripheral nerves by regulating lipid homeostasis and that its deficiency results in symptoms related to peripheral neuropathy.

Authors

Ali K. Jaafar, Aurélie Paulo-Ramos, Guillaume Rastoldo, Bryan Veeren, Cynthia Planesse, Matthieu Bringart, Philippe Rondeau, Kévin Chemello, Olivier Meilhac, Gilles C. Lambert, Steeve Bourane

Rheumatoid arthritis synovial fluid induces JAK-dependent intracellular activation of human sensory neurons

• Text
• PDF

Abstract

JAK inhibitors (JAKi) are widely used antiinflammatory drugs. Recent data suggest that JAKi have superior effects on pain reduction in rheumatoid arthritis (RA). However, the underlying mechanisms for this observation are not fully understood. We investigated whether JAKi can act directly on human sensory neurons. We analyzed RNA-seq datasets of sensory neurons and found that they expressed JAK1 and STAT3. Addition of cell-free RA synovial fluid to human induced pluripotent stem cell–derived (iPSC-derived) sensory neurons led to phosphorylation of STAT3 (pSTAT3), which was completely blocked by the JAKi tofacitinib. Compared with paired serum, RA synovial fluid was enriched for the STAT3 signalling cytokines IL-6, IL-11, LIF, IFN-α, and IFN-β, with their requisite receptors present in peripheral nerves postmortem. Accordingly, these recombinant cytokines induced pSTAT3 in iPSC-derived sensory neurons. Furthermore, IL-6 + sIL-6R and LIF upregulated expression of pain-relevant genes with STAT3-binding sites, an effect that was blocked by tofacitinib. LIF also induced neuronal sensitization, highlighting this molecule as a putative pain mediator. Finally, over time, tofacitinib reduced the firing rate of sensory neurons stimulated with RA synovial fluid. Together, these data indicate that JAKi can act directly on human sensory neurons, providing a potential mechanistic explanation for their suggested superior analgesic properties.

Authors

Yuening Li, Elizabeth H. Gray, Rosie Ross, Irene Zebochin, Amy Lock, Laura Fedele, Louisa Janice Kamajaya, Rebecca J. Marrow, Sarah Ryan, Pascal Röderer, Oliver Brüstle, Susan John, Franziska Denk, Leonie S. Taams

The distal nephron biomarkers associate with diabetic kidney disease progression

• Text
• PDF

Abstract

BACKGROUND While urinary biomarkers show promise in predicting diabetic kidney disease (DKD) progression, distal tubular markers remain understudied. We investigated the association of distal tubule markers, epidermal growth factor (EGF) and uromodulin (UMOD), with DKD progression in the Veterans Affairs Diabetes in Nephropathy (VA NEPHRON-D) clinical trial.METHODS. We used Cox regression models to evaluate the association between each biomarker and DKD progression and the relationship between change over time in biomarker and DKD progression. We used mixed models to investigate biomarker levels at baseline, 12 months, and over time and their relationships with longitudinal eGFR change.RESULTS. Participants (n = 1,116) had type 2 diabetes, urine albumin-to-creatinine ratio (UACR) ≥ 300 mg/g, and eGFR 30–89.9 mL/min/1.73 m2. Mean age was 65 years, mean eGFR was 56 (SD 19) mL/min/1.73 m2, and median UACR was 840 (IQR 424–1,780) mg/g. One hundred forty-four participants (13%) had DKD progression over a median follow-up of 2.2 (1.3–3.1) years. Higher baseline EGF and UMOD were independently associated with a lower risk of DKD progression (adjusted HR 0.68, 95% CI 0.47, 0.99 and 0.85, [0.75, 0.98] per 2-fold higher concentration of EGF and UMOD, respectively). Serial biomarker measurements were performed at baseline and 12 months, and a slower decline in biomarkers was associated with a lower risk of DKD progression when adjusted for baseline biomarker levels.CONCLUSION. Urinary EGF and UMOD may serve as valuable prognostic biomarkers in DKD.TRIAL REGISTRATION. ClinicalTrials.gov NCT00555217.FUNDING. NIH U01DK102730, U01DK103225, K23 DK118198, R01DK137087, U01DK103225, R37DK039773, U01DK114866, U01DK106962, U01DK129984, and R01DK093770; National Institute of Diabetes and Digestive and Kidney Diseases contract U01DK106965.

Authors

Christina L. Tamargo, Steven G. Coca, Heather Thiessen Philbrook, David G. Hu, Joachim H. Ix, Michael G. Shlipak, Linda F. Fried, Orlando M. Gutierrez, Sushrut S. Waikar, Sarah J. Schrauben, Jeffrey R. Schelling, Peter Ganz, Paul L. Kimmel, Jason H. Greenberg, Rajat Deo, Ayumi Takakura, Ramachandran S. Vasan, Joseph V. Bonventre, Chirag R. Parikh

Resident memory T cell development is gradual and shows AP-1 gene expression in mature cells

• Text
• PDF

Abstract

Tissue-resident memory T (TRM) cells play a central role in immune responses across all barrier tissues after infection. However, the mechanisms that drive TRM differentiation and priming for their recall effector function remains unclear. In this study, we leveraged newly generated and publicly available single-cell RNA-seq data generated across 10 developmental time points to define features of CD8+ TRM across both skin and small-intestine intraepithelial lymphocytes (siIEL). We employed linear modeling to capture gene programs that increase their expression levels in T cells transitioning from an effector to a memory state. In addition to capturing tissue-specific gene programs, we defined a temporal TRM signature across skin and siIEL that can distinguish TRM from circulating T cell populations. This TRM signature highlights biology that is missed in published signatures that compared bulk TRM to naive or nontissue resident memory populations. This temporal TRM signature included the AP-1 transcription factor family members Fos, Fosb, Fosl2, and Junb. ATAC-seq analysis detected AP-1–specific motifs at open chromatin sites in mature TRM. Cyclic immunofluorescence (CyCIF) tissue imaging detected nuclear colocalization of AP-1 members in resting CD8+ TRM greater than 100 days after infection. Taken together, these results reveal a critical role of AP-1 transcription factor members in TRM biology.

Authors

Neal P. Smith, Yu Yan, Youdong Pan, Jason B. Williams, Kasidet Manakongtreecheep, Shishir M. Pant, Jingxia Zhao, Tian Tian, Timothy Pan, Claire Stingley, Kevin Wu, Jiang Zhang, Alexander L. Kley, Peter K. Sorger, Alexandra-Chloé Villani, Thomas S. Kupper

Type 2 diabetes alters quiescent pancreatic stellate cells to tumor-prone state

• Text
• PDF

Abstract

Pancreatic stellate cells (PSCs) are the origin of cancer-associated fibroblasts. Type 2 diabetes mellitus (T2D) may promote pancreatic ductal adenocarcinoma (PDAC), eliciting changes in the quiescent PSC (qPSC) population from the precancerous stage. However, the details are unknown. We evaluated the subpopulations of qPSCs and the impact of T2D. PSCs isolated from 8-week-old C57BL/6J mice and diabetic db/db mice were analyzed by single-cell RNA-seq. Sorted qPSCs and PDAC cells were transplanted into allogenic mice. The isolated qPSCs were broadly classified into mesothelial cell and pancreatic fibroblast (Paf) populations by single-cell RNA-seq. Pafs were subclassified into inflammatory Pafs, myofibroblastic Pafs (myPafs) and a small population named tumor immunity- and angiogenesis-promoting Pafs (tapPafs), expressing Cxcl13. In the subcutaneous transplantation model, the tumors transplanted with myPafs were significantly larger than the tumors transplanted with tapPafs. An increase in myPafs and a decrease in tapPafs were observed from the precancerous stage in human T2D, indicating the effects of tumor progression. This study revealed the subpopulation changes in qPSCs in T2D. A therapy that increases the number of tapPafs could be a therapeutic option for patients with PDAC and T2D and even those in a precancerous stage of T2D.

Authors

Yutaro Hara, Hiroki Mizukami, Takahiro Yamada, Shuji Shimoyama, Keisuke Yamazaki, Takanori Sasaki, Zhenchao Wang, Hanae Kushibiki, Masaki Ryuzaki, Saori Ogasawara, Hiroaki Tamba, Akiko Itaya, Norihisa Kimura, Keinosuke Ishido, Shinya Ueno, Kenichi Hakamada

Imlunestrant a next-generation oral SERD overcomes ESR1 mutant resistance in estrogen receptor–positive breast cancer

• Text
• PDF

Abstract

Estrogen receptor α (ER) is a critical driver of tumorigenesis and tumor progression in most breast cancers. Endocrine therapies (ET) targeting ER are central to treating hormone receptor–positive breast cancer, but resistance poses a clinical challenge. Some resistance mechanisms, particularly those involving estrogen-independent activity such as the ESR1 mutations, rely on ER signaling, supporting the need for next-generation ET. We investigated the preclinical efficacy of imlunestrant, an oral selective ER degrader, in ER-positive breast cancer preclinical models, including models harboring the Y537S ESR1 mutation, an activating mutation. Imlunestrant demonstrated antagonistic activity and effective degradation of both WT and mutant ER, resulting in cell growth suppression. In vivo, imlunestrant outperformed fulvestrant, leading to tumor regression in a patient-derived xenograft harboring the Y537S ESR1 mutation. Cyclic mutiplexed immunofluorescence and transcriptomic analysis revealed enhanced cell cycle arrest and downregulation of estrogen-responsive genes with imlunestrant treatment. Additionally, a genome-wide CRISPR knock–out screen identified several vulnerabilities that were either persistent or acquired after imlunestrant treatment, providing a rationale for future studies of combination treatments with imlunestrant. Collectively, these results highlight the on-target and selective activity of imlunestrant, which can circumvent resistance engendered by the Y537S ESR1 mutation.

Authors

Shira Sherman, Zachary M. Sandusky, Douglas Russo, David Zak, Agostina Nardone, Delia Friel, Francisco Hermida-Prado, Capucine Heraud, Genevra Kuziel, Ana Verma, Giorgio Gaglia, Sheheryar Kabraji, Quang-De Nguyen, Sandro Santagata, Sean W. Fanning, Rinath Jeselsohn

TIAM1 drives prostatic branching phenotype and is a potential therapeutic target for benign prostatic hyperplasia

• Text
• PDF

Abstract

Benign prostatic hyperplasia (BPH) is the most common urologic condition in elderly men, characterized by the reactivation of developmental programs such as prostatic budding and branching. However, the molecular mechanisms underlying this reactivation in BPH remain unclear. In this study, we identified T-lymphoma invasion and metastasis-inducing protein-1 (TIAM1) as a critical regulator of prostatic budding and branching. By generating an unbiased BPH transcriptomic signature from patient datasets, we discovered an upregulation of TIAM1, which was subsequently validated at the protein level. Functional assays using organoid cultures derived from human prostatic cell lines revealed that TIAM1 is essential for prostatic budding and branching. Additionally, the BPH transcriptomic signature identified NSC23766, a small molecule inhibitor of TIAM1/RAC1 signaling, as a therapeutic proof-of-concept agent for BPH. Genetic knockdown of TIAM1 in human prostatic cell lines markedly reduced organoid branching, an effect mirrored by administration of NSC23766. The translational relevance of these findings is underscored by the growth inhibition observed in patient-derived BPH organoids treated with NSC23766. In conclusion, our findings identify TIAM1 as a key driver of prostatic branching and growth, and they suggest that targeting TIAM1/RAC1 signaling could be a promising therapeutic strategy for BPH.

Authors

Hamed Khedmatgozar, Sayanika Dutta, Michael Dominguez, Murugananthkumar Raju, Girijesh Kumar Patel, Daniel Latour, Melanie K. Johnson, Mohamed Fokar, Irfan Warraich, Allan Haynes Jr., Barry J. Maurer, Werner de Riese, Luis Brandi, Robert J. Matusik, Srinivas Nandana, Manisha Tripathi

Chemotherapy and the somatic mutation burden of sperm

• Text
• PDF

Abstract

Many chemotherapeutic agents impair cancer growth by inducing DNA damage. The impact of these agents on mutagenesis in normal cells, including sperm, is largely unknown. Here, we applied high-fidelity duplex sequencing to 94 samples from 36 individuals exposed to diverse chemotherapies and 32 controls. We found that in many of the sperm samples from men exposed to chemotherapy, the mutation burden was elevated as compared with controls and the expected burden based on trio studies, with 1 patient having a more than 10-fold increase over that expected for age. Saliva from this same individual also had a markedly higher mutation burden. We then validated this finding using other tissues, also finding an increased mutation burden in the blood and liver of many patients exposed to chemotherapy as compared with unexposed controls. Similarly, mice treated with 3 cycles of cisplatin had an increased mutation burden in sperm but also in the liver and hematopoietic progenitor cells. These results suggest an association between cancer therapies and mutation burden, with implications for counseling patients with cancer considering banking sperm before therapy and for cancer survivors considering the trade-offs of using banked sperm as compared with conceiving naturally.

Authors

Shany Picciotto, Camilo Arenas-Gallo, Amos Toren, Ruty Mehrian-Shai, Bryan Daly, Stephen Rhodes, Megan Prunty, Ruolin Liu, Anyull Bohorquez, Marta Grońska-Pęski, Shana Melanaphy, Pamela Callum, Emilie Lassen, Anne-Bine Skytte, Rebecca C. Obeng, Christopher Barbieri, Molly Gallogly, Brenda Cooper, Katherine Daunov, Lydia Beard, Koen van Besien, Joshua Halpern, Quintin Pan, Gilad D. Evrony, Viktor A. Adalsteinsson, Jonathan E. Shoag

Early multiple sclerosis activity associated with TBX21⁺CD21^loCXCR3⁺ B cell expansion resembling EBV-induced phenotypes

• Text
• PDF

Abstract

Epstein-Barr virus (EBV) infection precedes multiple sclerosis (MS) onset and plays a poorly understood etiologic role. To investigate possible viral pathogenesis, we analyzed single-cell expression in peripheral B cells from people with early MS collected longitudinally during the Immune Tolerance Network STAyCIS Trial. Expression profiles were compared with single-cell RNA-Seq (scRNA-Seq) from in vitro EBV models, autoimmune disorders, chronic infectious diseases, and healthy controls. Analyses focused on CD19+CD20+CD21loCD11c+T-bet+ atypical B cells (ABCs). ABCs were significantly enriched in early MS PBMCs versus healthy controls by scRNA-Seq and flow cytometry, establishing ABC expansion as a clinical feature. EBV-associated ABC expression, including CXCR3, programmed cell death ligand 1 (PD-L1), and PD-L2, was enriched in early MS; however, direct EBV infection of ABCs was not detected. Early MS ABCs exhibited significantly upregulated inflammatory cytokine mRNAs (CXCL8, IL18, VEGFA). Further, de novo EBV-infected B cells secreted IL-8 and VEGF. MS activity stratification revealed rare, distinctive inflammatory ABCs significantly underrepresented in individuals with no evidence of activity long-term versus people with additional relapsing-remitting MS activity at the primary endpoint. Moreover, CXCR3+ ABCs increased after baseline diagnosis and were significantly enriched in people with disease exacerbation during the study. Thus, ABC expansion and inflammatory responses correlate to early MS activity, possibly as a bystander response to EBV.

Authors

Elliott D. SoRelle, Ellora Haukenfrers, Gillian Q. Horn, Vaibhav Jain, James Giarraputo, Karen Abramson, Emily Hocke, Laura A. Cooney, Kristina M. Harris, Scott S. Zamvil, Simon G. Gregory, Micah A. Luftig

IL-1β signaling modulates T follicular helper and regulatory cells in human lymphoid tissues

• Text
• PDF

Abstract

Dysregulation of T follicular helper (Tfh) and T follicular regulatory (Tfr) cell homeostasis in germinal centers (GCs) can lead to antibody-mediated autoimmunity. While IL-1β modulates the GC response via IL-1R1 and IL-1R2 receptors on follicular T cells in animal models, its role in humans remains unclear. We analyzed Tfh and Tfr phenotypes in human secondary lymphoid organs (tonsils, spleen, and mesenteric lymph nodes) using flow cytometry, single-cell transcriptomics, and in vitro culture, comparing findings with samples from autoimmune patients. We observed organ-specific Tfh/Tfr phenotypes according to activation status and IL-1 receptor expression. An excess of IL-1R1 over IL-1R2 expression promoted a unique activated Tfr subset with Treg and GC-Tfh features. IL-1β signaling via IL-1R1 enhanced follicular T cell activation and Tfh-to-Tfr differentiation, while IL-1β inhibition upregulated IL-1R1, indicating a tightly regulated process. In autoimmune patients, high IL-1β and circulating Tfr levels correlated with increased autoantibody production, linking inflammation, IL-1β signaling, and Tfr/Tfh balance. Our findings highlight the critical role of IL-1β in follicular T cell activation and suggest that targeting IL-1β signaling in Tfh and Tfr cells could be a promising strategy for treating antibody-mediated autoimmune diseases.

Authors

Romain Vaineau, Raphaël Jeger-Madiot, Samir Ali-Moussa, Laura Prudhomme, Hippolyte Debarnot, Nicolas Coatnoan, Johanna Dubois, Marie Binvignat, Hélène Vantomme, Bruno Gouritin, Gwladys Fourcade, Paul Engeroff, Aude Belbézier, Romain Luscan, Françoise Denoyelle, Roberta Lorenzon, Claire Ribet, Michelle Rosenzwajg, Bertrand Bellier, David Klatzmann, Nicolas Tchitchek, Stéphanie Graff-Dubois

A spontaneous nonhuman primate model of inherited retinal degeneration

• Text
• PDF

Abstract

Inherited retinal degenerations (IRDs) are important causes of progressive, irreversible blindness. Hereditary macular diseases, in particular, are significant in their effect on the specialized, central cone photoreceptor–rich macula responsible for high resolution vision. Autosomal dominant Best vitelliform macular dystrophy (BVMD), caused by variants in the BEST1 gene, is one of the most common inherited macular dystrophies. Gene therapies have emerged as promising treatments for IRDs, but a lack of suitable animal models has hindered progress both in treatments and in understanding the mechanisms underlying macular diseases. Here, we report a Macaca fascicularis carrying a heterozygous potential pathogenic BEST1p.Q327E variant that disrupts the BEST1 ion channel by destabilizing the A195 helix, mirroring the structural perturbations seen in certain human pathological mutants. Longitudinal imaging over 2 years revealed progressive macular changes, including subfoveal cleft enlargement, lipid-rich deposit accumulation, retinal pigment epithelium (RPE) disruption, and central-to-peripheral photoreceptor degeneration, recapitulating early human BVMD pathology. Histopathology demonstrated diminished BEST1 expression, attenuation of the RPE-photoreceptor interface, and 2 distinct types of lipid deposits, including heretofore unappreciated cone mitochondrial-enriched lesions, highlighting selective cone mitochondria vulnerability. This is, to our knowledge, the first nonhuman primate model of inherited macular dystrophy, and it links BEST1 mutations, mitochondrial dysfunction, and progressive macular degeneration, offering new insights into BVMD pathophysiology and highlighting its utility for studying disease progression and potential therapeutic interventions.

Authors

Wei Yi, Mingming Xu, Ying Xue, Yingxue Cao, Ziqi Yang, Lingli Zhou, Yang Zhou, Le Shi, Xiaomei Mai, Zehui Sun, Wenjie Qing, Yuying Li, Aolun Qing, Kaiwen Zhang, Lechun Ou, Shoudeng Chen, Elia J. Duh, Xialin Liu

A TMPRSS6-inhibiting mAb improves disease in a β-thalassemia mouse model and reduces iron in healthy humans

• Text
• PDF

Abstract

β-Thalassemia is a genetic disorder arising from mutations in the β-globin gene, leading to ineffective erythropoiesis and iron overload. Ineffective erythropoiesis, a hallmark of β-thalassemia, is an important driver of iron overload, which contributes to liver fibrosis, diabetes, and cardiac disease. Iron homeostasis is regulated by the hormone hepcidin; BMP6/hemojuvelin–mediated (BMP6/HJV-mediated) signaling induces hepatic hepcidin expression via SMAD1/5, with transmembrane serine protease 6 (TMPRSS6) being a negative regulator of HJV. Individuals with loss-of-function mutations in the TMPRSS6 gene show increased circulating hepcidin and iron-refractory iron-deficiency anemia, suggesting that blocking TMPRSS6 may be a viable strategy to elevate hepcidin levels in β-thalassemia. We generated a human mAb (REGN7999) that inhibits TMPRSS6. In an Hbbth3/+ mouse model of β-thalassemia, REGN7999 treatment led to significant reductions in liver iron, reduced ineffective erythropoiesis, and showed improvements in RBC health, running distance during forced exercise, and bone density. In a phase I, doubleblind, randomized, placebo-controlled study in healthy human volunteers (NCT05481333), REGN7999 increased serum hepcidin and reduced serum iron with an acceptable tolerability profile. Our results suggest that, by both reducing iron and improving RBC function, inhibition of TMPRSS6 by REGN7999 may offer a therapy for iron overload and impaired erythropoiesis in β-thalassemia.

Authors

Heinrich E. Lob, Nikhil Singh, Kusha Mohammadi, Larisa Ivanova, Beth Crowell, Hyon J. Kim, Leah Kravets, Nanditha M. Das, Yonaton Ray, Jee Hae Kim, Sylvie Rottey, Emily Labriola-Tompkins, Hazem E. Hassan, Lorna Farrelly, Harvey F. Chin, Marilena Preda, Leigh Spencer Noakes, Kei Saotome, Matthew Franklin, Marc W. Retter, Elif Karayusuf, John J. Flanagan, William Olson, Kalyan C. Nannuru, Vincent Idone, Michael E. Burczynski, Olivier A. Harari, Lorah Perlee, Griet Van Lancker, Andrew J. Murphy, Aris N. Economides, Sarah J. Hatsell

Lipidomic profiling of human adiposomes identifies specific lipid shifts linked to obesity and cardiometabolic risk

• Text
• PDF

Abstract

BACKGROUND Obesity, a growing health concern, often leads to metabolic disturbances, systemic inflammation, and vascular dysfunction. Emerging evidence suggests that adipose tissue-derived extracellular vesicles (adiposomes) may propagate obesity-related complications. However, their lipid composition and effect on cardiometabolic state remain unclear.METHODS This study examined the lipid composition of adiposomes in 122 participants (75 in obesity group, 47 in lean group) and its connection to cardiometabolic risk. Adiposomes were isolated via ultracentrifugation and characterized using nanoparticle tracking and comprehensive lipidomic analysis by mass spectrometry. Cardiometabolic assessments included anthropometry, body composition, glucose-insulin homeostasis, lipid profiles, inflammatory markers, and vascular function.RESULTS Compared with lean controls, individuals with obesity exhibited elevated adiposome release and shifts in lipid composition, including higher ceramides, free fatty acids, and acylcarnitines, along with reduced levels of phospholipids and sphingomyelins. These alterations strongly correlated with increased BMI, insulin resistance, systemic inflammation, and impaired vascular function. Pathway enrichment analyses highlight dysregulation in glycerophospholipid and sphingolipid metabolism, bile secretion, proinflammatory pathways, and vascular contractility. Machine-learning models utilizing adiposome lipid data accurately classified obesity and predicted cardiometabolic conditions, such as diabetes, hypertension, dyslipidemia, and liver steatosis, achieving accuracy above 85%.CONCLUSION Obesity profoundly remodels the adiposome lipid landscape, linking lipid changes to inflammation, metabolic dysfunction, and vascular impairment. These findings underscore adiposome lipids as biomarkers for obesity and related cardiometabolic disorders, supporting personalized interventions and offering therapeutic value in risk stratification and treatment.FUNDING This project was supported by NIH grants R01HL161386, R00HL140049, P30DK020595 (PI: AMM), R01DK104927, and P30DK020595 as well as by a VA Merit Award (1I01BX003382, PI: BTL).

Authors

Abeer M. Mahmoud, Imaduddin Mirza, Elsayed Metwally, Mohammed H. Morsy, Giorgia Scichilone, Monica C. Asada, Amro Mostafa, Francesco M. Bianco, Mohamed M. Ali, Mario A. Masrur, Chandra Hassan, Brian T. Layden

Retraction of Deficient LRRC8A-dependent volume-regulated anion channel activity is associated with male infertility in mice

• Text
• PDF

Abstract

Authors

Jianqiang Bao, Carlos J. Perez, Jeesun Kim, Huan Zhang, Caitlin J. Murphy, Tewfik Hamidi, Jean Jaubert, Craig D. Platt, Janet Chou, Meichun Deng, Meng-Hua Zhou, Yuying Huang, Héctor Gaitán-Peñas, Jean-Louis Guénet, Kevin Lin, Yue Lu, Taiping Chen, Mark T. Bedford, Sharon Y.R. Dent, John H. Richburg, Raúl Estévez, Hui-Lin Pan, Raif S. Geha, Qinghua Shi, Fernando Benavides